Publication Date:
2022-05-26
Description:
Author Posting. © Cambridge University Press, 2003. This article is posted here by permission of Cambridge University Press for personal use, not for redistribution. The definitive version was published in Journal of the Marine Biological Association of the UK 83 (2003): 1347-1350, doi:10.1017/S0025315403008798.
Description:
Trophic positions (TP) were estimated for the blue shark (Prionace glauca), shortfin mako (Isurus oxyrinchus), thresher shark (Alopias vulpinus), and basking shark (Cetorhinus maximus) using stable isotope ratios of carbon ([delta]13C) and nitrogen ([delta]15N). The basking shark had the lowest TP (3·1) and [delta]15N value (10·4‰), whereas the thresher shark had the highest values (4·5, 15·2‰). Mako sharks showed considerable variation in TP and isotopic values, possibly due to foraging from both inshore and offshore waters. Thresher sharks were significantly more enriched in [delta]15N than blue sharks and mako sharks, suggesting a different prey base. The [delta]13C values of thresher sharks and mako sharks varied significantly, but neither was significantly different from that of blue sharks. No statistical differences were found between our TP estimations and those derived from published stomach contents analyses, indicating that stable isotope data may be used to estimate the trophic status of sharks.
Description:
This work was supported by National Marine Fisheries
Service Grant NA16MF1323 to M.E.L.
Keywords:
Prionace glauca
;
Isurus oxyrinchus
;
Alopias vulpinus
;
Cetorhinus maximus
;
Trophic positions
Repository Name:
Woods Hole Open Access Server
Type:
Article
Format:
129456 bytes
Format:
application/pdf
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